The Feasibility of Fill-for-Life Turbine Oils. Greg Livingstone Fluitec

The Feasibility of Fill-for-Life Turbine Oils Greg Livingstone Fluitec

Outline How long is Fill-for-Life anyway? Bleed & Feed Strategy Why do Turbine Oils Fail? Replenishing Antioxidants: 1. Feasibility 2. Qualification & Compatibility 3. Long-term performance Summary

What is the Life of Power Plants? Coal-Fired Power Plant were designed to last 30 years, however in practice they last much longer Average age of a coal plant in the US is 38 years old Average age of a retiring coal plant is 50 years old NGCC plants are also designed to last 30 years Also expected to last longer Nuclear Power Plants were designed to last 40 years Through re-licensing, most nuclear power plants will last longer

Average Age of Turbine Oil? Critical turbine components Hydro Steam Gas bearings guide vanes control system bearings control system bearings gears control system Speeds, rpm 50-600 >3,000 3000-7,000 Oil sump temp., C 40-60 40-70 50-95 Hot spot peaks, C 75-90 80-150 150-280 Unfavorable impact (water) Air (steam) Air air high temp. Oil Life (Years) 20+ 10-20+ 6-10

Fill-For-Life Objective Allow a turbine oil to operate for 40 years without performance problems and within condemning limits No flushes, confined space tank cleaning or oil reclamation No bleed & feeds

What is the End of Life? ASTM D4378 suggests the end of turbine oil life is when there are 25% remaining antioxidants. RULER (ASTM D6971) is the preferred test for this, however RPVOT (ASTM D2272) is still commonly used.

Options for oils with low AO levels Bleed & Feed Low AO Dump, Flush & Recharge Replenish Additives Costs

BLEED & FEED IS UNECONOMICAL 8

R&O Formulations Antioxidants Rust Inhibitors Foam Inhibitors Demulsifiers AW/EP Base Oil Additive Ref: Livingstone, Wooton

R&O Formulations Antioxidants Rust Inhibitors Foam Inhibitors Demulsifiers AW/EP In Bleed & Feed, the vast majority of turbine oil is healthy, just the AO s have depleted. You are replacing good base oil with more good base oil. Base Oil Additive Ref: Livingstone, Wooton

Gas Turbine Bleed & Feed Case Study 6,000 gallon reservoir Plant performed a 12% Bleed & Feed Test Before Bleed & Feed Estimated Results of Bleed & Feed Amines (%) 24 33 26 Phenols (%) 8 19 8 Results of Bleed & Feed

Degradation Products are Reactionary Sludge and varnish are reactionary molecules that will quickly deplete fresh antioxidants This lowers the value of bleed & feed even further Estimated cost for bleed & feed is 4X the price of new oil

How do Turbine Oils Degrade Contaminant Ingression Deposit Formation Oxidation & Thermal Degradation Antioxidant Depletion

Fill-for-Life Objectives Minimize & Remove Contaminant Ingression Minimize & Remove Deposit Formation Oxidation & Thermal Degradation Minimize & Remove Antioxidant Depletion Replenish

Fill-for-Life Objectives Minimize & Remove Minimize & Remove Deposit Formation Contaminant Ingression How can this be done efficiently and safely? Oxidation & Thermal Degradation Minimize & Remove Antioxidant Depletion Replenish

Criteria for Success 1. Antioxidants that are easy to add on-site without special blending equipment 2. Antioxidants must be compatible with inservice turbine oil and not cause any adverse reactions 3. Antioxidants must be stable in the formulation and provide long-term performance.

ADDING ANTIOXIDANTS TO IN- SERVICE TURBINE OILS 17

Additive Concentrate AO s must be blended into a soluble concentrate that can be easily dispensed into the turbine reservoir without any special equipment.

DETERMINING CANDIDACY FOR ANTIOXIDANT REPLENISHMENT 19

Adding AOs to In-Service Turbine Oils It is critical to have a formulator intimately familiar with antioxidant chemistries. Antioxidant formulations are balanced. It is important to rebalance the formulation. The carrier fluid must be compatible with the in-service oil. Antioxidant types and treat rates depend upon the original oil formulation and current oil condition. Up-front testing is necessary to predict results.

In-Service Oil Qualification Testing Used Oil Analysis Blending with AO Aging & Compatibility Testing (ASTM D7155) Post-Aging Analysis Appearance Ruler MPC Demulsibility Foam Viscosity TAN RPVOT FTIR Air Release Appearance Ruler MPC Demulsibility Foam Viscosity TAN RPVOT FTIR Air Release

In-Service Oil Qualification Testing Used Oil Analysis Blending with AO Aging & Compatibility Testing (ASTM D7155) Post-Aging Analysis Appearance Ruler MPC Demulsibility Foam Viscosity TAN RPVOT FTIR Air Release 1. No Negative Impacts 2. Significant AO response Appearance Ruler MPC Demulsibility Foam Viscosity TAN RPVOT FTIR Air Release

Qualified Oil Used Oil UO + Boost AO Compatibility of mixture, ASTM D7155 Fluid Clarity, rating/description 1 1 Sediment, rating/description 0 0 Result, pass/fail Pass Pass Water Content, ASTM D6304, ppm 18 15 Ruler, ASTM D6971 Area Amminic: 4615 (33%) 29589 (215%) Area Phenolic: 0 0 Membrane Patch Colorimetry, ASTM D7843 ΔE 39 6 Weight of Residue, mg/l 196 52

Qualified Oil Used Oil UO + Boost AO Demulsibility @ 54 C, ASTM D1401 Oil-Water-Emulsion/Time 24-27-31/30 42-35-5/30 Foaming Characteristics, ASTM D892 Sequence I, ml foam/time to break 240/0-184 170/0-116 Viscosity, ASTM D445 100 C Viscosity, cst 5.51 5.44 40 C Viscosity, cst 33.19 32.62 Viscosity Index 101 100 TAN, ASTM D664, mg/koh 0.17 0.18 RPVOT, ASTM D2272, minutes 199 893

Failing Qualification Test Used Oil UO + Boost AO Fluid Clarity, rating/description, ASTM D7155 1 3 Sediment, rating/description 0 0 Result, pass/fail Pass Fail RULER, Area Amminic: 2453 2313 RULER, Area Phenolic: 2754 12014 Membrane Patch Colorimetry, ΔE 16 31 Weight of Residue, mg/l 26 86 Demulsibility @ 54 C, ASTM D1401 40-40-0/15 40-40-0/15 Foaming Characteristics, ASTM D892 530-0-589 530-0-585 100 C Viscosity, cst, ASTM D445 7.02 6.9 40 C Viscosity, cst, ASTM D445 46.49 45.1 Viscosity Index 108 108 TAN, ASTM D664, mg/koh 0.11 0.09 RPVOT, ASTM D2272, minutes 622 589

Failing Qualification Test Used Oil UO + Boost AO Fluid Clarity, rating/description, Photo of Oil ASTM Before D7155 & After Test 1 3 Sediment, rating/description 0 0 Result, pass/fail Pass Fail RULER, Area Amminic: 2453 2313 RULER, Area Phenolic: 2754 12014 Membrane Patch Colorimetry, ΔE 16 31 Weight of Residue, mg/l 26 86 Demulsibility @ 54 C, ASTM Photo of D1401 Patch Before & After 40-40-0/15 Test 40-40-0/15 Foaming Characteristics, ASTM D892 530-0-589 530-0-585 100 C Viscosity, cst, ASTM D445 7.02 6.9 40 C Viscosity, cst, ASTM D445 46.49 45.1 Viscosity Index 108 108 TAN, ASTM D664, mg/koh 0.11 0.09 RPVOT, ASTM D2272, minutes 622 589

Compatible yet Unqualified Used Oil UO + Boost AO Fluid Clarity, rating/description, ASTM D7155 1 1 Sediment, rating/description 0 0 Result, pass/fail Pass Pass RULER, Area Amminic: 5656 13278 RULER, Area Phenolic: 2083 1551 Membrane Patch Colorimetry, ΔE 33 31 Weight of Residue, mg/l 84 103 Demulsibility @ 54 C, ASTM D1401 10-15-55/30 10-10-60/30 Foaming Characteristics, ASTM D892 280/0-151 300/0-175 100 C Viscosity, cst, ASTM D445 5.25 5.14 40 C Viscosity, cst, ASTM D445 31.51 31.14 Viscosity Index 95 90 TAN, ASTM D664, mg/koh 0.07 0.07 RPVOT, ASTM D2272, minutes 443 529

Compatible yet Unqualified Used Oil UO + Boost AO Fluid Clarity, rating/description, ASTM D7155 1 1 Sediment, rating/description 0 0 Result, pass/fail Pass Pass RULER, Area Amminic: 5656 13278 RULER, Antioxidant Area Phenolic: package wasn t 2083 rebalanced, 1551 Membrane Patch Colorimetry, ΔE 33 31 therefore Boost AO is not recommended. Weight of Residue, mg/l 84 103 Demulsibility @ 54 C, ASTM D1401 10-15-55/30 10-10-60/30 Foaming Characteristics, ASTM D892 280/0-151 300/0-175 100 C Viscosity, cst, ASTM D445 5.25 5.14 40 C Viscosity, cst, ASTM D445 31.51 31.14 Viscosity Index 95 90 TAN, ASTM D664, mg/koh 0.07 0.07 RPVOT, ASTM D2272, minutes 443 529

ASSESSING LONG-TERM PERFORMANCE OF ADDING AO 29

Measuring Long-Term Performance 1. Field Trials Realistic results however may take 10 years 2. Laboratory Stress Tests Needs to be correlated to field tests

Turbine Oil Performance Predictor The TOPP test was developed as a stress test to predict how turbine oils will perform in the field. Dozens of new oil samples have been stressed in the TOPP test Shows a wide range of performance with new turbine oils

Turbine Oil Performance Predictor (I) Test results have been correlated to in-service turbine oils. The test approximates 6 years of life in a large frame gas turbine The test approximates 9 years of life in a steam turbine

TOPP Test Parameters Test Parameters Turbine oil is maintained in a bath at 120 o C with an iron catalyst 6 weeks. Common weekly tests are: MPC RULER RPVOT FTIR Others can be added as desired

TOPP RESULTS WITH AO REPLENISHED TURBINE OIL

Results of TOPP Testing New Oil Used Oil Used Oil + AO Condemning Limit 35 60 100 112 165 Before TOPP After TOPP 0 50 100 150 200 AO % 0 3 6 9 12 Estimated Life (Years)

Results of TOPP Testing New Oil 35 100 Only 13% Life Left in New Oil after TOPP test. This oil would last for ~7 years in a Gas Turbine. Used Oil 60 Before TOPP Used Oil + AO 112 165 After TOPP 0 50 100 150 200 AO %

Results of TOPP Testing New Oil 35 100 Used Oil <50% remaining life or <3.5 years. Used Oil 60 Before TOPP Used Oil + AO 112 165 After TOPP 0 50 100 150 200 AO %

Results of TOPP Testing New Oil 35 100 Used Oil s AO levels increased to 165% of new with addition of AO. Used Oil 60 Before TOPP Used Oil + AO 112 165 After TOPP 0 50 100 150 200 AO %

Results of TOPP Testing New Oil 35 100 After TOPP Test, used oil still had more AO than new oil. Estimated Life after test is approximately 8 years. Used Oil 60 Before TOPP Used Oil + AO 112 165 After TOPP 0 50 100 150 200 AO %

Results of TOPP Testing New Oil 35 100 Lost 65% of AO Used Oil 60 Before TOPP Used Oil + AO 112 165 Lost 53% of AO After TOPP 0 50 100 150 200 AO %

Results of TOPP Testing New Oil 550 1250 Used Oil Used Oil + AO 475 812 845 Before TOPP After TOPP 0 200 400 600 800 1000 1200 1400 RPVOT Values It is well accepted that initial RPVOT values do not correlate to the life and performance of turbine oils. RPVOT retention is a more important consideration.

4-YEAR FIELD TEST RESULTS

Large Frame GT Case Study 4 year old oil in a large frame GT Oil was maintained in excellent condition AO was added to the fluid in 2010.

Current Oil Condition Ruler, ASTM D6971, Amines(%) Membrane Patch Colorimetry, ASTM D7843 RPVOT, ASTM D2272, minutes Mar 2010 Before AO Mar 2010 After AO Dec 2014 60% 181% 128% 8 5 6 475 865 979 Similar AO depletion rates as seen in the TOPP test. Excellent RPVOT retention.

Case Study Summary Field test results demonstrate similar AO depletion compared to laboratory TOPP tests Part of the success of this project has been due to proactive actions by the plant Use of a varnish mitigation system Elimination of spark discharge problems Excellent maintenance and condition monitoring program

SUMMARY 47

What s required for Fill-For-Life Turbine Oils? Fill-for-Life Turbine Oil - last for ~40 years, be maintained within spec and be problem free A key component of accomplishing this is replenishing depleted antioxidants In-situ antioxidant addition requires experience and expertise 48

Additive Replenishment Summary Up-front Qualification Testing is required prior replenishing antioxidants When an oil is qualified, in-situ AO addition provides excellent performance in laboratory stress tests (TOPP test) Field tests also show excellent performance and the results are similar to laboratory results The addition of antioxidants has been shown to at least double the life of in-service turbine oils.

Is it Feasible to have a Fill-for-Life Turbine Oil?

Is it Feasible to have a Fill-for-Life Turbine Oil? YES. Are we there yet? No.

To realize Fill-For-Life Turbine Oils... Multiple antioxidant treatments needs to be further studied before Fill-For-Life becomes a reality Timing of AO replenishment is based on condition monitoring Removing oil degradation products and depleted antioxidants plays an important role in realizing fill-for-life turbine oils Prescribing the correct dose at the correct time is critical to achieve Fill-for-Life 52